BEGIN:VCALENDAR VERSION:2.0 PRODID:-//linuxsoftware.nz//NONSGML Joyous v1.4//EN BEGIN:VEVENT SUMMARY:Dynamics of magnetospheres of rotating compact objects with Genera l Relativity DTSTART:20240716T093000Z DTEND:20240716T110000Z DTSTAMP:20260811T153556Z UID:cfdad933-9980-4d4c-89f3-8373b4d6b322 SEQUENCE:4 CREATED:20240716T173709Z DESCRIPTION:Rotating compact objects are known to fuel the most energetic extreme astrophysical phenomena in the universe. Their rotation induces an external electric field capable of efficiently accelerating particles\, p opulating the magnetosphere with e± plasma through quantum electrodynamic s (QED) processes and giving rise to the observed coherent and incoherent radiation.It is only possible to understand these first-principles phenome na using particle-in-cell (PIC) kinetic simulations of the global magnetos phere\, capturing magnetospheric current closure\, QED processes\, and gen eral relativity (GR). In this Thesis\, we have generalized the advanced PI C code OSIRIS to arbitrary curvilinear orthogonal coordinates\, suitable f or modeling plasma dynamics in magnetospheres of compact objects\, i.e. wi th significant spacetime curvature. The implementation detailed in this th esis extends the applicability of this tool beyond astrophysical scenarios . In particular\, to laboratory settings in more complicated geometries.We ran massively parallel simulations of pulsar magnetospheres\, performing numerical experiments to understand the role of general relativity and pla sma supply in the radio beam generation phase for low obliquity rotators. The results show that GR is fundamental to the appearance of the radio bea m in the first place for aligned rotators.For older stars\, it can even di stinguish a pulsar from a neutron star. In this thesis\, we also explored the effect of GR when the polar gap is in a non-stationary regime\, charac terized by having an (almost) vacuum gap at the base of the set of open ma gnetic field lines. Under these conditions\, the polar discharge occurs th rough a succession of isolated plasma filaments that do not follow the ste llar rotation\, usually used to explain drifting components of the beam.Th e results demonstrate the appearance of a new plasma filament\, giving a n atural explanation for the more bi-cone core emission configuration that a grees with the observations. LAST-MODIFIED:20240716T173958Z LOCATION:Amphitheater PA3 (Floor -1 of the Mathematics Building) URL:http://df.vps.tecnico.ulisboa.pt/en/events/dynamics-of-magnetospheres- of-rotating-compact-objects-with-general-relativity/ X-ALT-DESC;FMTTYPE=text/html:


Rotating compa ct objects are known to fuel the most energetic extreme astrophysical phen omena in the universe. Their rotation induces an external electric field c apable of efficiently accelerating particles\, populating the magnetospher e with e± plasma through quantum electrodynamics (QED) processes and givi ng rise to the observed coherent and incoherent radiation.

It is only possible to understand these first-principles phenomena using particl e-in-cell (PIC) kinetic simulations of the global magnetosphere\, capturin g magnetospheric current closure\, QED processes\, and general relativity (GR). In this Thesis\, we have generalized the advanced PIC code OSIRIS to arbitrary curvilinear orthogonal coordinates\, suitable for modeling plas ma dynamics in magnetospheres of compact objects\, i.e. with significant s pacetime curvature. The implementation detailed in this thesis extends the applicability of this tool beyond astrophysical scenarios. In particular\ , to laboratory settings in more complicated geometries.

We ran m assively parallel simulations of pulsar magnetospheres\, performing numeri cal experiments to understand the role of general relativity and plasma su pply in the radio beam generation phase for low obliquity rotators. The re sults show that GR is fundamental to the appearance of the radio beam in t he first place for aligned rotators.

For older stars\, it can eve n distinguish a pulsar from a neutron star. In this thesis\, we also explo red the effect of GR when the polar gap is in a non-stationary regime\, ch aracterized by having an (almost) vacuum gap at the base of the set of ope n magnetic field lines. Under these conditions\, the polar discharge occur s through a succession of isolated plasma filaments that do not follow the stellar rotation\, usually used to explain drifting components of the bea m.

The results demonstrate the appearance of a new plasma filamen t\, giving a natural explanation for the more bi-cone core emission config uration that agrees with the observations.

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